|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Aluminum Reduction Technology
||Current Efficiency in Hall-Héroult Cells: The Role of Mass Transfer at the Cathode
||Asbjorn Solheim, Henrik Gudbrandsen, Karen Sende Osen, Ole Edvard Kongstein, Egil Skybakmoen
|On-Site Speaker (Planned)
The current efficiency (CE) in aluminium cells is governed by transport of dissolved metal across the boundary layer at the cathode. The CE loss is influenced by ordinary mass transfer as well as by electronic conduction. The dependence of convection is not necessarily the same for the two loss mechanisms. A laboratory experiment was designed, where the mass transfer coefficient (k) in the so-called Sterten-Solli laboratory cell for measuring CE was varied in a controlled manner by means of a mechanical stirrer. The stirrer was calibrated by measuring the limiting current density in an aqueous system. It turned out that plots of the CE versus the mass transfer coefficient produced straight lines that extrapolated back to 99 percent CE at k = 0. This means that predictions of the CE can be made by using equations for ordinary mass transfer.
||Planned: Light Metals